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Friday, April 30, 2010

The Mobile, Alabama Press-Register has published an article by Ben Raines with an alarming prediction. If the leaking well in the Gulf of Mexico shrugs off all control - the crippled blowout preventer, the wellhead, and any remaining control valves or baffles impeding the flow of oil and gas through the well - the rate of spillage could go to a whole other level: as much as 2 million gallons (150,000 barrels) per day.

Schematic diagram of the leaking well and the relief-well drilling plan. Courtesy Times/Picayune.

This worst-case scenario is based on the fact that there are individual wells in the Gulf of Mexico that produce 1.26 million gallons (30,000 barrels) of oil per day. That's a controlled rate of flow. If all control were removed, the flow rate would be higher. How much higher?

"Typically, a very good well in the Gulf can produce 30,000 barrels a day, but that's under control. I have no idea what an uncontrolled release could be," said Stephen Sears, chairman of the petroleum engineering department at Louisiana State University.

Satellite image from early afternoon of April 29, 2010 shows oil slick very close to shore.

Today SkyTruth's president did an interview on CNBC. You can watch it here; our bit starts at about 4:20.

Gulf Coast folks, YOU CAN HELP show the world what's happening by joining the new Flickr group, Gulf of Mexico Oil Spill 2010. Upload your photos, video and observations to let everyone know the impacts of this spill. Learn to geotag your work, and we'll be able to pinpoint it on an interactive map.

SkyTruth is beginning to get radar satellite images showing the oil slick from the Deepwater horizon blowout and spill in the Gulf of Mexico. These images, from a variety of non-US satellites (don't get us started on that), cut right through clouds and haze to show the "texture" of the ocean surface. Oil flattens the ocean out (that's why they call it a "slick"); flat water looks black on radar images. This image, acquired by the European Space Agency's Envisat satellite, clearly shows the sprawling slick at about noon local time on April 26:

This, and other radar images that SkyTruth is getting, confirm what we've seen on the NASA/MODIS images so far, and support our conservative calculations showing that in the first week of this spill at least 6 million gallons have entered the Gulf. That's a spill rate of at least 850,000 gallons (20,000 barrels) per day, 20 times larger than the official Goast Guard estimate of 42,000 gallons per day.

The Exxon Valdez tanker spill totaled 11 million gallons. We could exceed that in just a few days, if we haven't already.

UPDATE 4/28/10 9:30 pm - A NASA/MODIS satellite image taken this afternoon has clouds, jet contrails and haze that obscure much of the oil slick, but shows the western edge of the slick is within 10 miles of shore.

Tuesday, April 27, 2010

Based on SkyTruth's latest satellite observations today of the size of the oil slick and published data on the thickness of floating oil at sea that produces a visible sheen (1 micron, or 0.000001 meters) we think the official estimate of the spill rate from the damaged well has been significantly too low.

Immediately after the Deepwater Horizon rig sank on April 22, the Coast Guard estimated that the well was leaking 336,000 gallons (8,000 barrels) of oil per day. But for the past few days they've estimated the rate at 42,000 gallons (1,000 barrels) per day. We think it's actually a lot closer to their original estimate.

We have a visible oil slick covering 2,233 square miles (5,783 km2). Given a minimum thickness of 1 micron (see chart below), that is 5,783 cubic meters of oil, or 1,527,706 gallons (36,374 barrels). The blowout happened almost 7 days ago on April 20. That's at least 5,000 barrels of oil per day - assuming none of it was consumed during the two-day fire that raged before the rig sank on April 22, and none has been collected by the response crews that have been working diligently for days.

Our calculation also assumes the entire slick is a sheen barely thick enough to be visible. Yet the images we've seen so far, especially the ALI image taken on April 21, suggest a strong spectral response from the oil slick, and that in turn suggests a much thicker slick. Today a BP exec claimed that 3% of the slick was 100 microns thick, and the remaining 97% is only one or two molecules thick. We're skeptical: 1 micron is the published, generally accepted lower limit for a visible sheen at sea:

CONCAWE chart of thickness and visible appearance of floating oil at sea. From a Minerals Management Service report, Real-time Detection of Oil Slick Thickness Patterns with a PortableMultispectral Sensor.

So if 3% of today's slick (173.5 km2) is 100 microns thick, and the remainder (5,609.5 km2) is 1 micron thick that's a total of 22,960 cubic meters of oil: 6,065,390 gallons. That's right: more than 6 million gallons spilled into the Gulf of Mexico so far.

This is what Dr. Ian MacDonald has to say. Ian is one of the world's foremost experts in remote sensing of oil slicks, and has spent his career exploring the Gulf of Mexico:

It turns out to be pretty easy to roughly estimate the amount of oil in a floating oil spill -- though like all estimates, large doses of caution should be applied. The critical variable is the thickness of the floating oil layer.

The CONCAWE guidelines from back in the late 80s are a reasonable place to start. CONCAWE gives a chart of thickness and appearance as shown in the figure. Notice that the minimum visible thickness is about 1um. If we take 1 um as a bare minimum starting place, think that a square meter of oil spill with a 1 um layer means that there is a 1000000/th of a cubic meter of oil floating in that spot. If you have 1 sq km of oil floating on the sea *and* it has a uniform thickness of 1 um, well, you have a million of those layers or 1 cubic meter. That makes 1000 liters of oil or about 264 gallons (6.2 bbl) per sq km of spill. We are seeing conservative estimates of 1000 sq km already on April 25th--I believe you measured 800 sq miles which is closer to 2000 sq km.

So for the minimum value on 25 April we have a minimum of 6,200 bbl of oil already on the water, which means that the 1000 bbl/day estimate we've been seeing is too low for an event that began on 21 April. However, this is probably a much too conservative estimate. This size in sq km of the floating oil spill may be greater by a factor of 2, as your estimate suggests. More important, the average thickness may be a factor of 10 or more greater. Certainly your more recent images suggest that the spill is locally dark and thick. Check the CONCAWE chart and you see that some of those sq km of ocean may represent 200 or 300 bbl of oil each.

So it would not be unreasonable to multiply that 6,200 bbl number by 20. This gets you up to 126,000 bbl in the water, which is about 5,300,000 gallons. That's roughly half the total Exxon Valdez spill. I do not think I am being too alarmist here--but you should check my numbers.

It will be critical to get some more recent images to see how much the slick has grown in the past couple of days.

We just processed a NASA/MODIS image taken from the Terra satellite this afternoon that shows slicks spread across 2,233 square miles, and within 22 miles of shore. See it here. The image suffers from clouds and haze (a problem we don't have to deal with on radar images) so we used somewhat more sophisticated spectral processing to identify the oil slicks. And no, it's not Photoshopped; we applied a modified Gaussian contrast-enhancement algorithm:

We just got a detailed ALI satellite image from NASA that was shot two days ago, on April 25, when the oil slick was about 817 square miles in size (it has since more than doubled to at least 1,800 square miles). You can see several response vessels working at the periphery of the slick. The magnitude of the job they have to do is plain to see.

Monday, April 26, 2010

SkyTruth just processed a NASA/MODIS satellite image of the Gulf of Mexico that was taken early yesterday afternoon (April 25). Slicks and sheen (very thin slick) covers about 817 square miles, and reaches 50 miles away from the assumed point of origin (the site of the leaking well on the seafloor). We've posted this in our image gallery for this incident. We've also shown the last two positions of the rig that we were able to detect before it sank, as seen on NASA images from April 21 (also in our gallery).

UPDATE 4/27/10 1pm - We've added a very detailed image to our gallery, also taken on April 25, from NASA's Advanced Land Imager (ALI) sensor carried on the Earth Observing-1 (EO-1) satellite. You can see response vessels, and gradations in the thickness of the slick and peripheral sheen. Meanwhile, the spill continues unabated, and the size of the oil slick has more than doubled since these NASA images were taken just two days ago. We hope to get new images soon.

Sunday, April 25, 2010

Yesterday the Coast Guard reported that the damaged well on the seafloor in the Gulf of Mexico is leaking oil again, at a rate estimated to be 42,000 gallons (1,000 barrels) per day. This is bad news - it means the blowout preventer on that well is not doing its job, and that several attempts by BP, Transocean and the Coast Guard to operate a shutoff valve on the well using a robotic ROV have failed. The oil slick has grown rapidly and now covers 400 square miles.

If the blowout and spill off Australia last year offer any lessons, it could be months before this well can be brought under control and the spill really and truly stopped. This is already a "major" oil spill by Coast Guard definition (>100,000 gallons), and a human tragedy. Economic losses include the $600-700 million dollar Deepwater Horizon drill rig, and as-yet untold millions in response and cleanup costs (and lawsuits from the people who have been hurt). But this blowout and spill in the Gulf now threaten to become truly catastrophic.

The NASA satellite imagery we used to track that Australia spill have been unavailable since Friday. As soon as we can get anything we'll do our best to get it posted here.

11 rig workers are still missing from the Deepwater Horizon explosion and fire off Louisiana. We are dismayed but still hoping for the best.

Just 5 months ago, as SkyTruth's President I was invited to give testimony on the risks posed by offshore drilling at a Senate hearing. My well-documented testimony included details on the blowout at a new rig and platform off Australia last year that resulted in a 10-week-long oil spill, ultimately covering 22,000 square miles of ocean with millions of gallons of oil. At the same hearing the Deputy Director of the Minerals Management Service, the President of Shell Oil Company, and the Vice President of Gulf operations for BP (David Rainey) touted their environmental records and the technical achievements that supposedly have rendered major offshore accidents a thing of the past.

One of the Senators in attendance at that pro-drilling hearing suggested I was misleading the American public and being intentionally untruthful. Now that same Senator is calling for a thorough investigation of the blowout and spill in the Gulf from the doomed Deepwater Horizon drill rig.

Thursday, April 22, 2010

A picture is worth 1,000 words.~First suggested by visionary Stewart Brand in 1966, this “Whole Earth” picture was taken in 1972 by Apollo 17 astronaut Harrison Schmitt.~This iconic image – humanity’s first glimpse of the entire planet – ushered in an era of environmental awareness.~At SkyTruth, we take a moment today to appreciate our small and miraculous home; to remember that all the life we know and care about is here, and here alone; and to renew our commitment to helping people see and understand our interdependence, inspiring positive action to protect the place that sustains us all.~Happy Earth Day!

The rig was built for drilling ultradeep wells in water far offshore, where most of the action is in the Gulf of Mexico. It's under contract to BP and was drilling an exploration well in the Macondo prospect, in the Mississippi Canyon area of the north-central Gulf. The water depth there is almost 5,000 feet.

SkyTruth's testimony to Congress last fall on the risks of offshore drilling was brushed off by some politicians. Maybe it's worth looking at again.

UPDATE 4/21/2010 - Despite some reports to the contrary, Coast Guard says 12 workers are still missing. 15 were injured, 7 of them critically.

UPDATE 4/21/2010 - NOAA reports that nearly 1.2 million gallons of fuel oil are on the rig (#2 fuel oil or diesel), and that the Coast Guard has requested NOAA's help in modeling oil spill trajectories in the event of a spill. I'm guessing that much of this oil is burning. See the official NOAA Incident Report. Thanks to blogger Seth Platt for the heads up.

UPDATE 4/21/2010, 7:10 pm - NBC Nightly News just reported that the rig is leaking oil into the water; and that the Coast Guard is trying to get an ROV or submersible that can shut off an underwater valve to cut the flow of fuel to the fire. This sounds like a "loss of well control," or blowout, like the one that lead to disaster off Australia last year. Let's hope they can get that valve closed. No word yet on the missing workers.

UPDATE 4/22/2010, 9:30 am - Coast Guard still searching for 11 missing rig workers; rig is still on fire. SkyTruth has started an image gallery for this incident that includes hi-res Coast Guard photos of the burning rig.

UPDATE 4/22/2010, 2:00 pm - CNN is reporting that the rig has sunk. The fire is continuing. Coast Guard is estimating that oil is spilling at a rate of 336,000 gallons (8,000 barrels) per day.

UPDATE 4/22/2010, 5:30 pm - SkyTruth analysis of two NASA satellite images taken hours apart yesterday suggests the Deepwater Horizon rig may have been drifting. Images show the rig moved almost 2-1/2 miles to the east in about 2 hours. We have no confirmation that the rig was drifting, and this would suggest a pretty fast clip. But the shorelines in the two images match up almost perfectly, so we have no exlanation yet for this apparent movement.

UPDATE 4/23/2010, 10 am - 11 rig workers still missing and Coast Guard reports that oil is no longer leaking from the damaged well on the seafloor. Not yet clear if this is because their attempt to shut off the well using an ROV has succeeded. Oil spill cleanup operations are proceeding with deployment of containment booms and skimmer vessels.

Wednesday, April 14, 2010

A lot of folks were surprised by the Obama administration's recently announced plan to expand oil and gas drilling in US waters to much of the Atlantic coast and into the Chukchi and Beaufort seas off Alaska. Alaska's Bristol Bay, home to a wild-salmon fishing industry that rakes in some $300-400 million every year, will be put off-limits to drilling until 2017.

Under this plan, drilling will be allowed off the Eastern Seaboard from Florida to Delaware:

We want to stress that our illustration is hypothetical. It's not based on a numerical model of how oil would likely move and disperse if a well off Delaware really did have a major problem; that's a function of wind, tide, current, the properties of the oil, the rate and quantity of spillage, and of course the effectiveness of our efforts to contain the oil in such an incident. But this illustration is based on actual observations of a real event, the Montara / West Atlas blowout and spill that we tracked in the Timor Sea off Australia last year.

Wednesday, April 7, 2010

We just learned about an oil spill yesterday in the Delta National Wildlife Refuge near Venice, Louisiana. The US Coast Guard is responding to the estimated 18,000-gallon spill of crude oil from a pipeline jointly operated by Chevron and BP. The cause of the spill is under investigation, but early reports suggest that workers on an Exxon barge may have accidentally damaged the pipeline.

This is yet another reminder of the risks that offshore drilling poses to onshore and coastal habitats and communities: the pipeline carries oil from an offshore platform out in the Gulf of Mexico.

Coast Guard Petty Officer 3rd Class James Peterson with Sector New Orleans, takes a sample from an oil spill that occured approximately 10 miles southeast of Venice, La., in the Delta National Wildlife Refuge, April 6, 2010. U.S. Coast Guard photo by Petty Officer 1st Class Jesse Kavanaugh.

The Coast Guard has posted high-resolution photos showing the impacts of this spill, which ranks as a "medium" spill by Coast Guard definition (an inland spill of 1,000 to 10,000 gallons); the kind of spill we usually don't hear about, unless it happens in an interesting location like an urban area, a popular beach, or a place that we all assume is protected, like a wildlife refuge. Looking at these pics it's difficult to imagine the impact of a multi-million-gallon spill like the Montara/West Atlas blowout and spill off Australia's coast last year.